package com.bst.datax.executor.service.jobhandler;

import com.bst.datatx.core.biz.model.ReturnT;
import com.bst.datatx.core.biz.model.TriggerParam;
import com.bst.datatx.core.handler.IJobHandler;

public class ExecutorStreamLoadHandler extends IJobHandler {

    /**
     * 先对数据按哈希值分片（不能确保所有数据都有id,为了通用性），后采用futures 并行处理
     * 缺乏doris环境无法公开测试，请各位参照DB模式自行开放该方案
     * @param tgParam
     * @return
     * @throws Exception
     */
    @Override
    public ReturnT<String> execute(TriggerParam tgParam) throws Exception {
        return null;
    }

//    3. 性能优化关键点
//    3.1 动态并行度调整
//    public int calculateOptimalParallelism(long dataSize) {
//        int availableCores = Runtime.getRuntime().availableProcessors();
//        long recordsPerThread = 100_000; // 每个线程处理10万条
//
//        int calculated = (int) Math.ceil((double) dataSize / recordsPerThread);
//        return Math.min(Math.max(calculated, 1), availableCores * 4);
//    }

//    3.2 批次大小控制
//    private static final int MAX_BATCH_ROWS = 50_000;
//    private static final long MAX_BATCH_BYTES = 100 * 1024 * 1024; // 100MB
//
//    public List<List<Map<String, Object>>> createBatches(List<Map<String, Object>> data) {
//        List<List<Map<String, Object>>> batches = new ArrayList<>();
//        List<Map<String, Object>> currentBatch = new ArrayList<>();
//        long currentSize = 0;
//
//        for (Map<String, Object> row : data) {
//            long rowSize = estimateRowSize(row);
//
//            if (!currentBatch.isEmpty() &&
//                    (currentBatch.size() >= MAX_BATCH_ROWS || currentSize + rowSize > MAX_BATCH_BYTES)) {
//                batches.add(currentBatch);
//                currentBatch = new ArrayList<>();
//                currentSize = 0;
//            }
//
//            currentBatch.add(row);
//            currentSize += rowSize;
//        }
//
//        if (!currentBatch.isEmpty()) {
//            batches.add(currentBatch);
//        }
//
//        return batches;
//    }

//    3.3 资源监控与背压
//            java
//    @Scheduled(fixedRate = 5000)
//    public void monitorThreadPool() {
//        ThreadPoolExecutor executor = (ThreadPoolExecutor) threadPool;
//
//        log.info("Thread pool status: " +
//                        "Active: {}, Queue: {}, Completed: {}, Total: {}",
//                executor.getActiveCount(),
//                executor.getQueue().size(),
//                executor.getCompletedTaskCount(),
//                executor.getTaskCount());
//
//        // 动态调整队列大小防止OOM
//        if (executor.getQueue().size() > 800) {
//            executor.setRejectedExecutionHandler(new ThreadPoolExecutor.AbortPolicy());
//        } else {
//            executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
//        }
//    }
//4. 异常处理增强
//4.1 分片级别重试
//            java
//    private void processShardWithRetry(String sourceTable, String targetTable, String condition) {
//        int maxRetries = 3;
//        int attempt = 0;
//
//        while (attempt <= maxRetries) {
//            try {
//                processShard(sourceTable, targetTable, condition);
//                return;
//            } catch (Exception e) {
//                attempt++;
//                if (attempt > maxRetries) {
//                    log.error("Failed to process shard after {} retries: {}", maxRetries, condition, e);
//                    throw e;
//                }
//                sleep(attempt * 1000L);
//            }
//        }
//    }
//4.2 失败分片记录
//            java
//    @Component
//    public class FailedShardRecorder {
//
//        private final JdbcTemplate jdbcTemplate;
//
//        @Async
//        public void recordFailedShard(String condition, String error) {
//            jdbcTemplate.update(
//                    "INSERT INTO shard_failures(shard_condition, error, fail_time) VALUES (?, ?, NOW())",
//                    condition, error);
//        }
//    }
//5. 完整调用示例
//            java
//    @RestController
//    @RequiredArgsConstructor
//    public class DataTransferController {
//
//        private final ParallelStreamLoadService parallelService;
//
//        @PostMapping("/transfer/parallel")
//        public ResponseEntity<String> startParallelTransfer(
//                @RequestParam String sourceTable,
//                @RequestParam String targetTable,
//                @RequestParam(defaultValue = "4") int parallelism) {
//
//            parallelService.parallelStreamLoad(sourceTable, targetTable, parallelism);
//            return ResponseEntity.ok("Parallel transfer completed");
//        }
//    }
}
